An electrowetting phenomenon is a phenomenon which utilizes a change in contact angle of a hydrophobic surface against a polar liquid (and a non-polar liquid) that is induced by, for example, application of a voltage to the polar liquid and non-polar liquid (usually colored) that are immiscible with each other on an electrode having the hydrophobic surface.
Elements utilizing this electrowetting phenomenon show high brightness and high contrast ratio as well as large viewing angle, high switching rate and the like, and display elements utilizing this phenomenon have relatively low power consumption because they do not require front or backlight. Therefore, such elements are used in a variety of optical application fields, including optical switches for optical fibers, optical shutters or filters for cameras and guide devices, optical pickup elements, optical waveguide materials, video display pixels and the like.
For example, Patent Documents 1 to 3 disclose display elements utilizing such a phenomenon.